25.06.2013 Views

Walia Special Edition on the Bale Mountains (2011) - Zoologische ...

Walia Special Edition on the Bale Mountains (2011) - Zoologische ...

Walia Special Edition on the Bale Mountains (2011) - Zoologische ...

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

A lot of data we collect in protected areas has a spatial reference. For instance we could count<br />

<strong>the</strong> number of Ethiopian wolf pups at a den that has a specific locati<strong>on</strong>. This is called geographic<br />

data since it describes an event occurring at an explicit positi<strong>on</strong> <strong>on</strong> <strong>the</strong> earth’s surface. Essentially,<br />

geographical data are any informati<strong>on</strong> that can be assigned a unique x and Y coordinate. Geographic<br />

data can be complicated as <strong>the</strong>re are many different descripti<strong>on</strong>s of <strong>the</strong> earths surface (projecti<strong>on</strong>s<br />

and datums), however if you are collecting geographic data choose <strong>on</strong>e system and stick with it.<br />

Latitudes and l<strong>on</strong>gitudes measured in degrees, minutes, and decimals are <strong>the</strong> most universal metric<br />

and can be c<strong>on</strong>verted to any o<strong>the</strong>r projecti<strong>on</strong> easily. Most protected areas use this system. If you are<br />

interested in knowing more about geographic data a good overview is compiled in <strong>the</strong> lecture notes<br />

posted <strong>on</strong> <strong>the</strong> Geographer’s Craft website through <strong>the</strong> University of Colorado (http://www.colorado.<br />

edu/geography/gcraft/c<strong>on</strong>tents.html).<br />

Knowing <strong>the</strong> different types of data is important because as data becomes more detailed it<br />

also becomes increasingly more complicated and expensive to collect (Figure 1). This raises <strong>the</strong><br />

questi<strong>on</strong>, how do you know at which scale to collect your data?<br />

Which Scale to Collect Data?<br />

Knowing <strong>the</strong> appropriate level of detail to collect data can be troublesome. Data can be infinitely<br />

precise and as researchers and managers we can be naively drawn to its allure, a bit like a dizzy moth<br />

to a light bulb, but it’s a dangerous game.<br />

To illustrate this point, <strong>the</strong> Serengeti Ecological M<strong>on</strong>itoring Program (which is part of <strong>the</strong><br />

Serengeti Nati<strong>on</strong>al Park General Management Plan) depends <strong>on</strong> understanding <strong>the</strong> relati<strong>on</strong>ship<br />

between fires and changes in <strong>the</strong> vegetati<strong>on</strong> communities. Using l<strong>on</strong>g-term data <strong>on</strong> wildebeest<br />

numbers, fire events and photo points, researchers where able to re-create <strong>the</strong> complex dynamics<br />

of Acacia forest regenerati<strong>on</strong> (Dublin et al. 1990). The data required were elephant and wildebeest<br />

censuses c<strong>on</strong>ducted <strong>on</strong>ce every 2 to 5 years for about 40 years, estimates of percent of <strong>the</strong> area<br />

burnt each year, and a collecti<strong>on</strong> of photos taken from <strong>the</strong> same points every 10 years (roughly).<br />

Now imagine a similar situati<strong>on</strong> where <strong>the</strong> same data were measured at a finer scale: wildebeest<br />

were counted 10 times a year for 40 years (400 censuses), fires were measured every m<strong>on</strong>th for 40<br />

years (480 times), and diameter at breast height for 10,000 trees was measured every year. The<br />

resulting amount of data would be vast, <strong>the</strong> effort involved in collecting and editing <strong>the</strong> data would<br />

be immense, and <strong>the</strong> motivati<strong>on</strong> required in order to analyze such a data set would be heroic. In fact,<br />

chances are that if <strong>the</strong> data are too complex <strong>the</strong>y will never get used. And if we did analyze it, we<br />

would probably find very similar results to <strong>the</strong> very simple data collected.<br />

Under <strong>the</strong> first data collecti<strong>on</strong> scheme we would be collecting less detailed data, in a broader<br />

area, <strong>on</strong> a l<strong>on</strong>ger time schedule, and with much less effort. The sec<strong>on</strong>d scheme, however, would<br />

provide very detailed data, in a very localized geographic area, <strong>on</strong> a very short time schedule, and<br />

with a huge amount of effort. Therefore, scale can operate both spatially from localized effects to<br />

regi<strong>on</strong>al effects, as well as temporally from frequent measures to rare measures. We can think about<br />

<str<strong>on</strong>g>Walia</str<strong>on</strong>g>-<str<strong>on</strong>g>Special</str<strong>on</strong>g> <str<strong>on</strong>g>Editi<strong>on</strong></str<strong>on</strong>g> <strong>on</strong> <strong>the</strong> <strong>Bale</strong> <strong>Mountains</strong> 310

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!